One foot have 26 bones and 3 foot arches, they are :
a) Medial Longitudinal Arch;
b) Lateral Longitudinal Arch and;
c) Transverse Arch
Formation of Foot shape
Functions of foot arches
Similiar to spring, which is responsible for shock absorption and body propulsion during walking. Foot with collapsed arch (i.e. Flat Foot or pronated foot) lacks of elasticity in foot arches, extra energy are required to propulsion. Collapsed foot arches is one of the reasons for muscle fatigue.
Body Propulsion during Walking or Running (Stage 1 to 5)
1) Heel land on ground – Heel region land on ground first, pressure are on lateral side of the foot heel. (more wear out of shoes at heel on lateral side are common & reasonable)
2) Foot palm land on ground – Arches will collape a bit to absorb the force effectively. Pressure will shift from lateral side of Mid foot to Medial side of Mid foot.
3) Support weight – At this stage foot will bear whole body weight. Pressure are all on medial side of foot.
4) Heel leave ground – Propulsion of body forward, pressure shift to Big toe joint, phalanges & shaft (Fore foot area)
5) Foot leave ground – Foot leave the ground completely & starts to swing outwards & repeat stage 1). At this point, the other foot are at stage 3)